1. Field of Invention
This invention relates to hand held, toy gliders having an aerodynamic design. More specifically, the present invention relates to a toy glider constructed of buoyant material which enables the glider to travel in a controlled path either under water or in the air.
2. Prior Art
Toy glider aircraft have always been among the most popular playthings for children. Even prior to the development of actual aircraft by the Wright brothers and their contemporaries, toy glider aircraft have intrigued both young and old.
The essential feature of glider aircraft is a light weight design which permits a floating response of the airplane once it has been launched with sufficient forward thrust. The desired lightweight properties were originally developed by hollow body construction such as illustrated in U.S. Pat. No. 1,497,774. The development of improved plastics and molding techniques spawned the generation of a new type of glider design which was injection molded or otherwise formed of lightweight plastics. An example of such construction is shown in U.S. Pat. No. 149,848. This patent introduces a delta wing design wherein the wings are swept back to reduce drag and to render a more streamlined appearance.
A further line of improvement with respect to toy glider aircraft revolves around the concerns of safety and durability. It is well known that numerous lightweight gliders formed of thin balsa wood components fly well; however, they are easily broken by impact either during flight or during landing. Furthermore, such component construction is always subject to misalignment by impact at a wing which dislodges the balanced aerodynamic configuration of the aircraft. Accordingly, one aspect of toy glider aircraft design has focused on the issue of the durability of the aircraft during flight and upon landing as well as safety within the user environment. U.S. Pat. No. 3,246,425 is illustrative of design efforts to develop a more rugged construction for glider aircraft which can survive the various impact situations which can arise during use. Such characteristics included a thickened fuselage section with blunt nose capable of absorbing impact without breaking. This patent also illustrates an additional structural aspect of reinforcing wings with tail fins which not only improve aerodynamic performance but also protect wing structure from inadvertent breakage.
The slightly earlier design is represented in U.S. Pat. No. 3,909,976 wherein the glider structure is made of foam material and includes a weighting element to give proper balance to the glider structure. The forward construction of the glider is given a large radius to reduce potential aircraft damage upon impact. It should be noted, however, that this latter aircraft is not aerodynamically configured and is more correctly classified as a "throwable" toy intended for in-house use. It is apparent from its construction that it was not intended to embody a glider having aerodynamic response such as lifting or soaring properties.
The concept of generating rounded edges is represented in U.S. Pat. No. 194,401 wherein a planar airplane design having an upright tail is disclosed. This construction is more accurately identified as a saucer craft and is not designed for gliding or soaring as our conventional toy gliders. The primary focus of this design appears to be in its survivability, regardless of the type of impact which it may undergo.
More recent aircraft design are represented in the delta wing structures represented in U.S. Pat. No. 3,898,763. This patent discloses a high performance type aircraft designed for enhanced soaring properties. It includes a nose pod which provides a fuselage to this structure and a pair of swept back wings which extend away from the nose pod. The soaring enhancement arises from a moderate reflex provided along the trailing edges of the wings in the order of 3.degree. to 5.degree.. This structure is blow molded with styrofoam construction and includes a wooden dowel imbedded within the nose pod to provide proper weight distribution and balance. Modified design configurations of this craft are shown in U.S. Pat. Nos. 240,437; 240,441; 240; 240,439.
Finally, U.S. Pat. No. 4,332,103 discloses another form of delta wing glider having a fuselage which extends the full length of the wing and incorporates a blunt nose for protecting the aircraft against impact damage. As with U.S. Pat. No. 3,898,763, this construction is a unibody aircraft having the advantages of avoiding dislocation of wing orientation to maintain an optimum aerodynamic state. The construction of this latter aircraft is of resilient cellular material such as foam rubber, providing resilience against breakage and an ability to mold proper wing and body configuration to enhance aerodynamic performance.
This historical review of glider aircraft demonstrates a traditional allegiance to certain design criteria which continues to dominate the current state of the art. Specifically, toy gliders generally have a nose pod or forward fuselage which provides weight and balance to the forward section of the aircraft and is designed to absorb the initial impact with trees, buildings, or the ground. this nose pod projects forward of the front leading edge of the wing or a line representing a central extension of this leading edge. Accordingly, the fuselage is of sturdy construction and generally includes some form of blunt nose projecting forward of the wing structure which is designed to absorb the impact without causing fracture or other damage to the airplane In contrast, wing structure is generally attached in a rear position along the fuselage to avoid its impact and destructive effect because its more fragile nature. This tradition is clearly represented in U.S. Pat. Nos. 3,898,763 and 4,332,103 which represent high performance model aircraft fabricated of foam rubber or styrofoam construction in a unibody form. In each instance, the nose is designed to bear the primary load of impact and the wing structure is swept back to minimize its exposure. Accordingly, a dominant design aspect for toy gliders dictates that the fuselage extend forward of the wing structure to provide protection upon impact and offer whatever balancing benefit there may be by adopting this configuration.
A further characteristic feature generally represented in all forms of toy gliders has been the absence of their adapted flight in an underwater environment. In other words, toy gliders have characteristically been designed with aerodynamic properties with performances limited to an atmospheric environment. The present inventor is unaware of any effort to configured a toy glider with fluid dynamic characteristics which enable the same glider to travel a controlled flight course whether in atmospheric conditions or under water. The absence of such design characteristics for toy gliders is somewhat surprising in view of the thousands of swimming pools which become primary playground locations for children. The development of a glider aircraft which can also be flown "underwater" is a concept which has been generously portrayed in animated video adventures; however, has been conspicuously absent in real life play.